Abstract
INTRODUCTION: Recent media reporting has suggested an increase in the incidence of rare cancers in 2021 as a result of the COVID-19 pandemic, raising concern for possible carcinogenic effects of severe acute respiratory syndrome coronavirus 2 infection. We aimed to identify cancers that increased in incidence in the United States during 2021 compared with 2018-2019. METHODS: We analyzed data from Surveillance, Epidemiology, and End Results (SEER-22) using a systematic classification schema including rare cancers. We estimated age-standardized incidence rate ratios (aIRRs) comparing the year 2021 to 2018-2019 for 693 individual cancer types and highlight those with an aIRR > 1 based on a Bonferroni-corrected P-value threshold. Cancer types of particular interest included cholangiocarcinoma, diffuse large B-cell lymphoma, Kaposi sarcoma, and lung cancer. RESULTS: Among 693 unique cancer types evaluated, 9 showed a significant increase in incidence in 2021 compared with 2018-2019 and did not also increase in prior years, including 4 subtypes of thymoma (type-A aIRR = 2.50; type-AB aIRR = 2.78; type-B aIRR = 1.90; type not otherwise specified aIRR = 1.60), granulosa cell tumor of the ovary (aIRR = 2.72), peripheral neuroectodermal tumors of the bone (aIRR = 10.6) and soft tissue (aIRR = 3.20), pheochromocytoma (aIRR = 4.59), and paraganglioma (aIRR = 3.30). Increases for all 9 cancer types could be attributed to changes in cancer registry reporting practice. Cancer types of particular interest did not increase in incidence during 2021. DISCUSSION AND CONCLUSION: Our study does not support an increase in cancer incidence in the United States in 2021 due to the COVID-19 pandemic. It is important to monitor future trends, which may reveal longer-term effects of COVID-19.